The present invention relates to a mechanism for converting a weight into a frequency comprising a tuning fork vibrator formed integrally therewith.
Heretofore, there has been proposed to measure a weight by utilizing a phenomenon that a natural frequency of a tuning fork is varied in accordance with a tension or compression force applied to the tuning fork as disclosed in Japanese Patent Application Laid-open Publications Nos. 133,390/79 and 51,329/80. In the weight measuring apparatus using the tuning fork, if the weight is correctly applied to the fork in its axial direction, there can be obtained an accurate measuring result. However, if a twisting or bending force is applied to the vibrating fork or if an undesired force perpendicular to the axial direction of the fork is applied thereto, there might be produced various measuring errors which give a hindrance for practical use. Moreover, when the vibrating fork is secured to a measuring apparatus, for instance a weighing apparatus, the fork is subjected to undesired internal stress. Further the internal stress is different from respective securing operations and therefore, the characteristics of the tuning forks might be varied for respective forks. In some cases, there might be produced hysteresis and creeps and the resolution might be lowered. It should be further noted that since the various portions are made of materials having different thermal expansion coefficients, error might be introduced due to temperature variation.